Outflow valve assembly for a toilet tank

ABSTRACT

A toilet tank outflow valve assembly for a flush toilet system is disclosed, wherein the outflow valve assembly includes a lower valve assembly portion, said lower portion having an outer sealing surface and an inner sealing surface, said outer and inner sealing surfaces adapted to contact a bottom of the toilet tank to form a first and second seal where the outflow valve assembly meets the bottom of the toilet tank.

TECHNICAL FIELD

The present invention relates to an outflow valve for a toilet tank of a flush toilet system. More particularly, the invention provides an outflow valve system having a seal with at least two sealing regions to prevent leakage where the outflow valve system couples to the toilet tank.

BACKGROUND OF THE INVENTION

Toilet tank outflow valves permit the selective discharge of water from a toilet tank into a toilet bowl. Many types of outflow valves are known, including but not limited to flapper-style valves. Outflow valves typically are coupled to the bottom of the toilet tank via an outflow tube that extends through an opening in the bottom of the toilet tank. A rubber gasket or other seal is typically used between the outflow tube and the edges of the opening in the toilet tank bottom to prevent water from leaking out of the toilet tank. The seal may be tightened by tightening a threaded nut around the bottom of the outflow tube, where it extends out of the bottom of the toilet tank.

Over time, impurities and corrosive materials in the water in the tank, even in low concentrations, may corrode, wear and/or otherwise degrade the seal. Furthermore, mechanical damage cause by lack of care during toilet repair, etc. may also damage the seal. Damage to the seal may allow water to leak around the seal. This can result in wasted water due to the periodic partial re-filling of the tank once enough water has leaked to actuate the toilet tank fill valve, and also may lead to water damage of structures and items in the vicinity of the toilet. Furthermore this partial refilling can also be a nuisance and disturb people working or living in areas where they can hear the noise of the partial refilling, and may cause wear to the fill valve due to the constant cycling on and off.

One option to solve this problem is to replace the seal. Due to the low cost of toilet outflow valves, a damaged seal is typically replaced by replacing the entire outflow valve system. However, replacing the entire outflow valve system can be a cumbersome task, in some cases requiring the services of a skilled plumber. As a result, the seal system of prior approaches has significant technical and cost disadvantages.

SUMMARY

Some embodiments provide a toilet tank outflow valve assembly for a flush toilet system, wherein the outflow valve assembly includes a lower valve assembly portion, said lower portion having an outer sealing surface and an inner sealing surface, said outer and inner sealing surfaces adapted to contact a bottom of the toilet tank to form a first and second seal where the outflow valve assembly meets the bottom of the toilet tank.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a toilet having a toilet outflow valve system according to an embodiment of the present invention.

FIG. 2 is a side view of the embodiment of FIG. 1.

FIG. 3 is a partially cut-away side view of a first embodiment of an outflow valve gasket according to the present invention.

FIG. 4 is a partially cut-away side view of a second embodiment of an outflow valve gasket according to the present invention.

FIG. 5 is a partially cut-away side view of a third embodiment of an outflow valve gasket according to the present invention.

FIG. 6 is a partially cut-away side view of a fourth embodiment of an outflow valve gasket according to the present invention.

FIG. 7 is a partially cut-away side view of a fifth embodiment of an outflow valve gasket according to the present invention.

FIG. 8 is a partially cut-away side view of a sixth embodiment of an outflow valve gasket according to the present invention.

DETAILED DESCRIPTION OF THE DEPICTED EMBODIMENTS

Various embodiments of the present invention provide sealing systems for use with many types of toilet tank outflow valve systems, including but not limited to the single and dual flush-volume toilet tank outflow valve systems disclosed in U.S. Pat. No. 6,637,042 to Hand, the disclosure of which is hereby incorporated by reference. Furthermore, various embodiments of the sealing system configurations offer improved durability, functionality, replaceability, and retrofitability compared to known dual valve assemblies.

A first embodiment of an outflow valve system according to the present invention is shown generally at 10 in FIG. 1 as a single flush-volume flapper-type outflow valve system, positioned in a toilet tank 12. Outflow valve system 10 includes a base 14 with which it may be mounted to the inside of toilet tank 12. An outflow tube section 16 extends upwardly from base 14, and a flush valve 18 is coupled to the outflow tube section adjacent the bottom of the interior of toilet tank 12. Flush valve 18 is configured to empty essentially all water from toilet tank 12 when opened. An overflow tube section 20 is coupled to outflow tube section 16. Outflow valve system 10 also includes a toilet bowl refill tube 24 configured to refill a toilet bowl after a flush.

FIG. 1 also shows an example of a suitable setup for the operation of valve system 10 in a toilet. Flush valve 18 is attached to a single flush wand 26 operated by a handle 28. Flush valve 18 is connected to the flush wand with a chain or cord 32, which may have an adjustable amount of slack.

FIGS. 2 shows outflow valve system 10 in more detail. As mentioned above, outflow valve system 10 includes a base 14 configured to couple the valve assembly 10 to a bottom 40 of toilet tank 12 and to pass water out of the toilet tank via an outflow hole 43. In the depicted embodiment, base 14 takes the form of a spud, but it will be appreciated that base 14 may have any other suitable configuration. Base 14 includes a threaded portion 42 that fits through toilet tank outflow hole 43, and is secured to bottom 40 of toilet tank 12 with a nut 44. The connection may be sealed with a gasket 46. Gasket 46 forms an improved seal with tank bottom 40 compared to known gaskets, as discussed in more detail below with regard to FIG. 3.

Outflow tube section 16 is connected to base 14, and includes a hollow upright portion 48 to which overflow tube section 20 is coupled. Outflow tube section 16 also includes a side tube 50 extending away from upright portion 48, which connects flush valve 18 to upright portion 48. Side tube 50 may have any suitable configuration, and may be positioned at any desired location on outflow tube section 16. In the depicted embodiment, side tube 50 is oriented generally parallel to toilet tank bottom 40, and is positioned directly adjacent the toilet tank bottom. This places the lower edge of the lip 52 of valve 18 close to the bottom of toilet tank, and thus permits essentially all of the water to drain from the tank when the high volume flush valve is opened. However, it can also be placed directly touching tank bottom 40, or several inches above tank bottom 40. While flush valve 18 is connected to upright portion 48 with lower side tube 50 in the depicted embodiment, it will be appreciated that the flush valve may also be attached directly to the side of upright portion 48, without the use of lower side tube 50.

Flush valve 18 is configured to cover the end of lower side tube 50 to control the discharge of water through the lower side tube. Flush valve 18 is thus positioned at the free end of lower side tube 50, and is pivotally anchored to a pair of arms 57 located on upright portion 48. In the depicted embodiment, flush valve 18 is a flapper valve, but may be any other suitable type of valve.

FIG. 3 shows gasket 46 in more detail. Specifically, gasket 46 forms a first and second seal with tank bottom 40. The first seal is formed between a first, outer sealing surface 310 on an outer rim 302 of gasket 46 and tank bottom 40, and the second seal is formed between a second, inner sealing surface 312 on a lower portion 316 of the gasket and the edge of hole 43 in the toilet tank bottom.

Outer rim 302 may have any suitable shape, including but not limited to the annular (or ring-like) shape shown in FIG. 3. The depicted outer rim 302 includes a shoulder 304 between the flat portion of an upper surface 306 of outer rim 302 and an outwardly sloped surface 308 of the outer rim. Shoulder 304 as shown has a continuous curve, but may also have a single corner or a segmented curve. Outer rim 302 also may have a varying thickness around shoulder 304 to help strengthen the interface forces, and thus the seals at sealing surfaces 310 and 312.

The depicted sealing surfaces 310 and 312 are separated by a space or voided region 314. The use of voided region 314 between sealing surfaces 310 and 312 may help to increase the effectiveness and durability of gasket 46. For example, if water from toilet tank 12 gets between surface 310 and tank bottom 40, void 314 may help to break any capillary pathway between gasket 46 and tank bottom 40. This may help to prevent water from leaking out of toilet tank 12 should the seal at surface 310 fail. Furthermore, voided region 314 may help to isolate the corrosive effects occurring at sealing surface 310 from sealing surface 312, thereby improving the life of sealing surface 312. As such, the overall seal life may be greatly increased.

As described above, second sealing surface 312 is formed between a lower portion 316 of gasket 46 and tank bottom 40. The lower portion 316 of the depicted gasket 46 is inwardly angled toward a centerline of gasket 46, whereas the outer rim 302 is outwardly angled. However, these parts may have any other suitable degree and direction of angle, including those illustrated in several alternative embodiments described below. In the embodiment of FIG. 3, the flat portion of sealing surface 312 contacts a corner at the hole 43 in the tank bottom 40. As such, the sealing contact is of a circular shape having a line of contact. Depending on the pressure applied, and the deformation of the tank bottom and gasket 46, the contact surface can increase to form a larger contact area extending partially over tank bottom 40 and the sides of hole 43.

The gasket 46 may be formed of any suitable material. Examples of suitable materials include, but are not limited to, water-impermeable materials such as polyvinyl chloride (PVC), Teflon, various other plastics, silicone, rubber and other elastomeric materials, or combinations thereof. Additionally, outer rim 302 and lower portion 316 may be integrally formed as a single piece, or may be separate pieces and separately formed, as described below with regard to FIG. 4. Likewise, gasket 46 can be integrally formed in outflow valve assembly 10, or can be a separate piece that is attached to base 14 or outflow tube section 16.

Gasket 46 has a center through-hole, as indicated by the dashed lines 320, for accepting base 14. Gasket 46 can also be held in place on base 14 in any suitable manner. In the depicted embodiment, gasket 46 is held in place via compressive forces exerted against the top of gasket 46 by side tube 50 and a flange 54 that extends around the lower portion of valve assembly 10. Other examples include, but are not limited to, threaded connections and frictional interactions between through-hole 320 and base 14.

In the depicted embodiment, outer rim 302 and lower portion 316 of gasket 46 each has a circular shape. This forms circular first and second seals, as well as an annular-like voided region 314 between inner sealing surface 312 and outer sealing surface 310. Also note that lower portion 316 (and surface 312) protrude downward farther into through-hole 43 than surface 310.

The surface finish of the various surfaces of gasket 46 may vary in any suitable manner. For example, sealing surfaces 310 and 312 may be finished either to a higher smoothness than the remaining surfaces of gasket 46, or to a lower smoothness.

Typically, nut 44 is tightened to compress outer rim 302 and lower portion 316 of gasket against toilet tank bottom 40 with sufficient pressure to form a watertight seal. Furthermore, the particular shape of the embodiment of FIG. 3 may allow the water in tank 12 to create pressure on gasket 46 to help strengthen the seal(s) to tank bottom 40. The force of water pushing against gasket 46 is directed generally downward and inward on outer rim 302, due to the angled shape of outer rim 302. The forces on gasket 46 thus generally create forces directed in a direction to press sealing surfaces 310 and 312 against toilet tank bottom 44 to increase the effectiveness of both seals 310 and 312.

The use of two sealing surfaces, 310 and 312, helps to create a redundant seal between outflow valve system 10 and toilet tank 12, and thus may help to lengthen the life of gasket 26. In the early life of gasket 46, sealing surface 310 forms the primary seal to prevent water from leaking from the tank 12. However, as the gasket life continues, and the corrosive effects of impurities in the water gradually degrade sealing surface 310, sealing surface 312 becomes the primary sealing surface. In this way, the dual sealing nature of gasket 46 may provide significantly increased gasket life, and thereby may reduce the frequency at which valve assembly 18 needs replacement. As such, toilet owners can spend less money replacing toilet parts, and spend less money by avoiding calls to plumbers to fix toilet leaks.

In the embodiment of FIG. 3, sealing surface 310 is generally parallel to tank bottom 40, whereas sealing surface 312 is angled with respect to the tank bottom. As such, sealing surface 312 is formed at a circular intersection of tank bottom 40 and hole 43. Gasket 46 may obtain several synergistic effects due to these two seals. First, the angular seal at sealing surface 312 may create a higher interface pressure due to the lower contact surface area. This may allow for the formation of a tight seal that stabilizes the positioning and location of gasket 46 in the system. Further, this firm locating effect may allow the outer sealing surface 310 to be accurately located and firmly positioned so that the higher surface area, flat interface at sealing surface 310 can provide an effective seal. In this way, the seals formed by sealing surfaces 310 and 312 can effectively seal the system with improved durability and longer lasting leakage protection.

Example size ranges are now illustrated for the example embodiment of FIG. 3. Circular sealing surface 310 may have an approximate width from 1 mm to 30 mm, including 2-3, 3-4, 4-5, 5-6, 6-7, 7-8, 8-9, 9-10, 10-11, 11-12, 12-13, 13-14, 14-15, 15-16, 16-17, 17-18, 18-19, 19-20, 20-21, 21-22, 22-23, 23-24, 24-25, 25-26, 26-27, 27-28, 28-29, 29-30, 1-10, 10-20, and 20-30 mm, and in-between. However, the surface can also be wider or more narrow, if desired, such as illustrated in the examples below. Also, the outwardly sloping angle at 308 can vary from the approximately 60 degrees illustrated in FIG. 3. For example, it can range between 10 degrees and 90 degrees, including 10-20, 20-30, 30-40, 40-50, 50-60, 60-70, 70-80, 80-90, 30-70, degrees and in-between. Further, varying degrees of slope can be used, such as illustrated in FIGS. 7 and 8, for example. Also the degree of protrusion of portion 316 below surface 310 can be varied, along with the inwardly sloping angle of surface 312. For example, the slope of approximately 45 degrees shown in FIG. 3 can vary between 10 and 90 degrees, including 10-20, 20-30, 30-40, 40-50, 50-60, 60-70, 70-80, 80-90, 30-70, degrees and in-between.

Thus, as indicated above, while FIG. 3 shows lower portion 316 having an outer surface inwardly angled that has a flat sealing surface 312 for contacting the edge of hole 43, various other alternatives can also be used. For example, sealing surface 312 can have a slight notch to allow increased surface area contact with the corner of hole 43 and tank bottom 40. In this way, an increased surface contact area can be provided, although in one example, still lower than the surface contact area at sealing surface 310. Alternatively, outer surface 312 can have a curved shape or various other shapes, as described in more detail below.

FIG. 4 shows, generally at 400, a second embodiment of a gasket according to the present invention, wherein the gasket is formed of two separate pieces, outer sealing member 402 and inner sealing member 404. By using a separate component to form the outer seal, it is possible to retrofit prior art toilet systems with outer sealing member 402 alone to enclose the prior art gasket. This may provide significantly increased life for an ordinary toilet outflow valve gasket. Referring to FIG. 4, the outer sealing member 402 forms a first seal at surface 310, and inner sealing member 404 forms a second seal at surface 312. Members 402 and 404 can be held in assembly 18 via compression forces, via a threaded connection, or via friction. Still other coupling mechanisms can be used, including but not limited to glue or other adhesives.

Outer sealing member 402 includes a through-hole 408 to accommodate base 14 or outflow tube 16. Inner sealing member 404 has a corresponding through-hole, as indicated by the dashed lines at 410.

Referring now to FIG. 5, a third embodiment of a gasket is shown generally at 46 a, where lower portion 316 a has an outer surface sloping inwardly from top to bottom where surface 312 a is curved, rather than flat as shown in FIG. 3. The curved surface may provide increased locating forces to more accurately and precisely locate gasket 46 a in hole 43 in tank bottom 40.

Referring now to FIG. 6, a fourth embodiment of gasket is shown, generally at 46 b, where lower portion 316 b has an outer surface sloping inwardly from top to bottom at two angles. The upper portion 330 of surface 312 b has a higher sloping angle than the lower portion 332. In this way, the sealing surface 312 b, as well as the locating of gasket 46 b in hole 43 in tank bottom 40, can potentially be improved since the angled surface is positioned at the corner of hole 43. Note also that the lower portion 332 can also be simply vertical.

Referring now to FIG. 7, a fifth embodiment of gasket is shown, generally at 46 c, where the outer rim 302 c has an even greater varying thickness, coming to a contact point 310 c, which forms a seal with the tank bottom. Thus, curved portion 304 c is shown with a downward slope surface 308 c that ends perpendicular to toilet tank bottom 40. This embodiment provides two sealing surfaces 310 c and 312 c, each forming a seal at a narrow, point-like (or circular line-like) surface, rather than across a broader surface area. This provides greater contact forces on each seal, which can be advantageous to provide a strong seal with less clamping force.

Referring now to FIG. 8, a sixth embodiment of gasket is shown, generally at 46 d, combining the outer surface features of FIG. 7 with a notched lower portion. Specifically, lower portion 316 d has an outer surface sloping inwardly from top to bottom where surface 312 d is has a notch 340. Thus, in this embodiment, the outer seal has a point contact with tank bottom 40, and the inner seal has a surface area contact.

The various embodiments of gasket 46 can be manufactured in various ways. In one example, the gasket is injection molded, thus forming in it final shape in a single step. In another example, a blank is first formed, and then machined to provide the desired shape. For example, referring to FIG. 3, the through-hole can be formed in a blank via a drill press or punch operation. Next, the part may be placed on a lathe and outer rim 302 formed by removing material from the blank. Then, a notch may be taken out on the lathe to form surface 310. Finally, the lathe can remove material to create the void 314, including the sloping surface 312.

Although the present disclosure includes specific embodiments, specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various elements, features, functions, and/or properties disclosed herein. For example, there can be combinations, and sub-combinations, of the features shown in FIGS. 3-8. Thus, the notched surface 312C of FIG. 8 can be used with the outer surface 304 shown in FIG. 3. Likewise, the outer surface having a pointed outer contact seal as indicated by 304A and 308A of FIGS. 7 and 8 can be used with the curved inner surface of FIG. 5. As still another example, the sealing systems and gaskets described herein can be used in various types of toilets, such as automatic flushing toilets. Also, an automatic indicator can be used to indicate when replacement is needed. As yet another example, additional seals could be used in addition to the first and second seals described above.

The following claims particularly point out certain combinations and subcombinations regarded as novel and nonobvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure. 

1. A toilet tank outflow valve assembly for a flush toilet system, the flush toilet system including a toilet tank, the outflow valve assembly comprising: a lower valve assembly portion, said lower portion having an outer sealing surface and an inner sealing surface, said outer and inner sealing surfaces adapted to contact a bottom of the toilet tank to form a first and second seal where the outflow valve assembly meets the bottom of the toilet tank.
 2. The outflow valve assembly of claim 1 where said first seal encircles said second seal.
 3. The outflow valve assembly of claim 2 wherein a voided region is formed between said first seal and said second seal.
 4. The outflow valve assembly of claim 3 wherein said outer sealing surface has a width that forms a ring shaped contact area with a bottom of said toilet tank.
 5. The outflow valve assembly of claim 4 wherein said outer sealing surface is formed on an outer rim of a first protrusion from said lower portion of said valve assembly.
 6. The outflow valve assembly of claim 5 wherein said inner sealing surface is formed on a downwardly pointing second protrusion from said lower portion of said valve assembly.
 7. The outflow valve assembly of claim 6 wherein said downwardly pointing protrusion has an inwardly sloping surface forming said second surface.
 8. The outflow valve assembly of claim 5 wherein said first protrusion has an outwardly sloping surface forming said first surface.
 9. The outflow valve assembly of claim 6 wherein said first and second protrusions are formed integrally.
 10. The outflow valve assembly of claim 6 wherein said first and second protrusions are formed separately.
 11. The outflow valve assembly of claim 11 wherein said gasket is at least partially constructed of at least one material selected from the group consisting of elastomeric materials and rubbers.
 12. A gasket for an outflow valve in a flush toilet system, the flush toilet system including a toilet tank, the gasket comprising: an outer portion having an outwardly sloping rim, said outwardly sloping rim having a first sealing surface adapted to contact an interior surface of the toilet tank to form a first seal; and an inner portion having an inwardly sloping second sealing surface that protrudes further than said rim, said inwardly sloping second surface adapted to be coupled to a hole in said toilet tank to form a second seal, said second seal being encircled by said first seal thereby defining a voided region.
 13. The gasket of claim 12 wherein the outer portion and the inner portion are formed integrally.
 14. The gasket of claim 12 wherein the outer portion and the inner portion are formed separately.
 15. The gasket of claim 12 wherein said outer portion has a curved outer region between said outwardly sloping rim and a top surface of said gasket.
 16. The gasket of claim 12 wherein gasket is at least partially formed of at least one material selected from the group consisting of rubber and elastomeric materials.
 17. The gasket of claim 12 wherein the first sealing surface and the second sealing surface are spaced apart.
 18. The gasket of claim 12 wherein the gasket is adapted to be replaceably coupled to the outflow valve.
 19. The gasket of claim 18, wherein the outer portion is adapted to be replaceably coupled to the outflow valve separately from the inner portion.
 20. A method of retaining water in a toilet tank, the method comprising: forming a first seal between a flush valve and said toilet tank; and forming a second seal between said flush valve and said toilet tank, said second seal being encircled by said first seal.
 21. The method of claim 20, further comprising forming a space between the second seal and the first seal. 